1. Field of the Invention
The present invention relates to a motor drive device for a motor for a washing machine of a double-rotor/double-stator structure that can selectively rotate a pulsator and a dehydrator without having a separate clutch, and a motor control method thereof.
2. Description of the Related Art
In general, a direct-drive washing machine selectively rotates a pulsator and a dehydrator by using a single motor for the washing machine.
For example, a motor for a washing machine repeatedly rotates a pulsator in a forward and reverse direction when the washing machine performs a laundry operation and a rinsing operation of washes, and rotates the pulsator and a dehydrator in an identical direction at high-speed when the washing, machine performs a dehydration operation of the washes.
In order to rotate only the pulsator or both the pulsator and the dehydrator, by using the single motor for the washing machine, conventional direct-drive washing machines include a clutch, respectively (see Korean Patent Registration No. 10-0438616 on Jun. 23, 2004).
The clutch plays a role of rotating the pulsator when the rotating torque of the motor for the washing machine is delivered to the rotating shaft of the pulsator, or rotating both the pulsator and the dehydrator at high-speed when the rotating torque of the motor for the washing machine is delivered to the rotating shaft of the pulsator and the rotating shaft of the dehydrator.
However, the clutch includes a coupling unit, a coupling lifting lever, a lifting lever drive unit, and so on and includes a torque transmission unit having a sun gear, as planetary gear, a carder, and so on, in order to deliver the rotating torque of a rotor to the pulsator during performing a laundry operation. As a result, the configuration of the clutch becomes very complicated and the price thereof is expensive, to thereby cause manufacturing costs for the washing machine to rise up.